Apparatus for facilitating communication between telephone-exchanges.



A. T. M. THOMSON. APPARATUS FOR FACILITATING COMMUNICATION BETWEEN TELEPHONE EXCHANGES.

APPLICATION FILED AUG. 28, 1906. 935,285, Patented Sept. 28, 1909.

7 z SHEETS-SHEET 1.

A. T. M. THOMSON. APPARATUS FOR FACILITATING COMMUNICATION BETWEEN TELEPHONE EXCHANGES.

v v APPLIUATION FILED AUG. 28, 1906. 935,285.

sNvEmTOR WITNESSES CMJL UNITED STATES PATENT OFFIGE.

ARTHUR THOMAS MILNOR THOMSON OF LONDON. ENGLAND.

APPARATUS FOR FACILITATING COMMUNICATION BETWEEN TELEPHONE-EXCHANGES.

Specification of Letters Patent. Patented Sept, 28, 1909,

Application filed August 28, 1906. Serial No. 332,363.

To all Whom. it may concern:

Be it known that I, AIrrnUR THOMAS MIL- rzou Tnonsox. a sub ect of the King of Great liritain, residing at 22 and 23 Charles street. llatton Garden, in the county of London. England, have invented new and useful Improved Apparatus for Facilitating Communication Between Telephone-Exchanges, of which the following is a specification. I

This invention relates to telephone apparatus whereby any one of a limited number of telephgne operators, in the neighborhood of one another, can in turn obtain the exclusive use of the wire circuit leading from that neighborhood to another station and returning through earth, or as is usual by a second Wire.

The contrivance is adapted to enable each in turn, of the subscribers who are connected with a telephone exchange on the party system, to place himself in communication with the exchange and exclude, as long as his requirements demand, all the other subscribers ofthe party, without necessitating the employment of a human intermediary. It is also even more particularly adapted to enable any tors at a home exchange to obtain each in turn, the exclusive possession of the call or order wire which connects that exchange with a distant exchange or with another branch of the home exchange.

The principle of operation consists in providing in the neighborhood of the several operators of the set or party an instrument.- in which is mounted what may be described as a visiting organ which organ is, by some convenient mechanical energy, caused to travel on circuit and in turn presentitself successively to the service of each operator of the set or party. each operator being pro-' vided with means for rendering the engagement. of such service automatic when so presented subsequently to being desired.

The accompanying drawings show a form of construction whereby the above described functions can be efficiently performed, the instrume'nt'shown, of which the diameter of the disk is about 7 inches being adapted to serve the requirements of 40 associated operators and the visiting organ moving in an efficient manner at the rate of one revolution per second when-not arrested;

In these drawings :-Figure 1 is a sectional end elevation taken along the line 1-1 of Fig. 2. Fig. 2 is a plan. Fig. 3 a

tained in some convenient source one of. a set of opera-- are. secured, also in side elevation, parts being omitted. Fig. 4 is a diagrammatic representation of the instrument showing the electric connections, and :Fig. 5 is a section showing a detail of the construction of the instrument.

In these figures for each of a number of operators, three contact studs 0 7) 0 a b &c. are provided: These are secured symmetrically in an insulated manner around av disk (I which is secured to a frame a in which is mounted a spindle f adapted to be maina state of uniform rotation by .of energy transmitted by a band to the pulley f. To the spindle is secured the crown-toothed ratchetwheel f and on the spindle is mounted a sleeve 9 adapted to slide and turn thereon, having near one enda ring groove g wherewith the extremities of a pivoted fork 72 can engage and effect the longitudinal displacement of the sleeve while permitting it to freely rotate. At the other extremity of the sleeve is secured a crown-toothed ratchetwheel 9 adapted to engage with. f and cause the sleeve to be rotated thereby. To the end of the sleeve, opposite to 9 is secured an- Qther crowntoothed wheel 9 having V-shaped teeth adapted. to engage with a similar toothed disk 0 which is secured to the frame a and the sleeve thereby be brought to rest in one of a number of precise angular positions, such number being equal to the number of teeth in the wheels 0 g and equal to the number of sets of studs a b o &c. and number of operators. To the sleeve is secured, in an insulated manner, three spring arms (I 7) c the extremities of which are adapted to make metallic contact with. one ofthe sets of studs a if 0-,.&c., a 6 with (1 b, 620., respectively, when the sleeve is arrested, and r with a, &c., successively, when the sleeve is rotating. On the sleeve an insulated manner, three rings a" b" 'c" which are electrically connected to the arms a be respectively. In permanent rubbing contact with the rings 1/ I)" c" are three spring mounted brush contactsm y 2". v

The above mentioned pivoted fork 71 con stitutes one arm of a bell-crank lever-the other 11 carrying an armature /F- of an electromagnct '1'. *When this latter is energized. the attraction of the armature will draw the sleeve out (if-engagementwith the rotating spindle and cause its abrupt arrest by vtl'octing an engagement between the teeth of y" and e and, when subsequently the electromagnet becomes denergized by the breaking of the circuit, the spring y will withdraw the armature and displace the sleeve to re new engagement with the rotating spindle through the medium of the ratchet-wheels f g and cause the arms a Z) 0 to re-commence visiting the sets of stud contacts a b c &c.

The electrical connections will now be described, especial reference being therein made to Fig. 4 but also to the other figures. In the description it will, as a representative example, be supposed that a calling operator is in possession of the call or order wire, the

. arms a b a being arrested in contact with the studs a", Z), c respectively. In such a case an electric circuit will be established through the winding of the telephone of the calling operator and an operator at a distant or branch exchange, through the to and return call or order wires 0: y which are ermanently joined to the before mentione brush contacts 00 yand through electric leads 0: w from the telephone of the calling operator which are permanently joined to the studs a b respectively, the circuit being temporarily completed by the movement of the arms a 1) into contact with the studs a The completion of the above described telephone circuit was effected by energizing the electromagnet i from a local source of electrical energy It by the completion of another electrical circuit in the following man'- ner:Each operator is in command of a separate circuit closing press key, that forming a portionpf the equlpment of the calling operator being denoted m and shown on Fig. 4. One side of the gap, adapted to be closed by the key, is permanently joined to the contact stud c by the wire a and the other side by a wire 0 to one of the poles of a battery Z1, the other pole of the battery being joined by a wire to the Winding of the electromagnetic and led therefrom to the before mentioned brush contact 2. It will thus be seen that should akey be pressed, as

for example the key m by the calling operator, then when subsequently the arm 0 in its periodica visitation brushes the contact stud e", the local circuit will forthwith become completed and the consequent energizing of the electroma gnet will efiect the completion of the telephone circuit as before de scribed. When the calling operator release? the key m the arms a b will spring out 0' contact and resume their circular journey until again arrested when arm 0 next brushes the stud of another operator who has previously pressed the key at his command.

To facilitate the making and the tracing of the electrical connections board 1' is provided and sets of three wires connect this board to the sets of studs in the manner indicated in Fig. 1. The arm 0 extends in a direction opposite to that of the arms a I) in order to balance the pressures when the telephone circuit is completed.

Fig. 5 by-a section taken through the contact stud-s a .7) and 0 shows in detail the method of fixing the studs of the disk. This latter is composed of a metal plate (Z whereby-it is secured to 3 rods 6 which form a portion of the frame 6 and two vulcanite plates (1 The holes in the metal plate are bored to a large diameter so that on inserting the studs and screwing them tightly, the vulcanite plates and the wiring strips 8 will be firmly secured without danger of contact of the stud-shanks with the metal plate 17.

I claim.

In an apparatus of the class described for facilitating communication between each of several operators at a central exchange and a single operator at a distant exchange. a rotary visiting organ, three contact springs.

carried by said organ, for each contact spring, a ring concentrically mounted on the visiting organ to which rings each of said contact springs is permanently electrically connected, call or order wires connecting the two exchanges, three fixed brush contacts, two of which are in electrical connection with said call Wires, a local, circuit including the third brush contact, an electromagnet coil and the sourceof electrical energy included in said local circuit, the whole being so arranged that after the voluntary closure of a gap in the local circuit by; an operator, the subsequent autonrfiie closure of a second gap in the same circuit y the visiting organ;- energizes the electroinagnet and? thereby completes the telephone circuit of the said operator.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ARTHUR THOMAS MILNOR THOMSON.

Witnesses:

lionmu'r A. Briana, l. J. Osman. 

